1. Field of the Invention
This invention relates to and has among its objects a novel immune globulin and novel methods for its production. Particularly, the invention is concerned with an intravenously injectable immune globulin having a high titer of naturally occurring antibody to respiratory syncytial virus (RSV). Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.
2. Description of the Prior Art
Respiratory syncytial virus is considered the most important cause of severe respiratory disease in infants and young children. It can also be an important cause of lower respiratory tract disease in the elderly. In the United States alone it has been reported that this virus causes pneumonia, bronchitis and croup in approximately 4 million children each year, resulting in about 4500 deaths. In the western world it is the major cause for hospitalization of children [National Research Council News Report, 35, 9 (1985), Stott, E. J. et al, Archives of Virology, 84:1-52 (1985), and W. H. O. Scientific Group, World Health Organization Technical Report Series 642 (1980)].
In industrial areas of Great Britain the annual rate of hospital admissions of children between 1 and 3 months of age, as a result of RSV infection, has been reported to be 24.5 per 1000 children [Stott, E. J. et al, Archives of Virology, 84:1-52 (1985)].
At the present time there is no vaccine available to prevent this disease. An inactivated vaccine developed nearly 25 years ago not only was ineffective, but appeared to potentiate more severe disease in vaccinated children as compared with placebo controls [Kapikian, A. Z. et al, American Journal of Epidemiology, 89:405-21 (1969) and Kim, H. W. et al, American Journal of Epidemiology, 89:422-34 (1969)].
Although the disease is most severe during the first few months of life, at a time when moderate levels of maternal antibody are present, recent studies in an animal model indicate that maternal antibody is ineffective below a critical level [Prince, G. A., et al, Journal of Virology, 55:517-20 (1985)].
Hemming et al, [J. Infectious Diseases, 152, 1033 (1985)], disclose the results of a study of passive immunotherapy for respiratory syncytial virus infections in the respiratory tract of a primate model, which showed that the infusion of human intravenous immune globulin (prepared from plasma having an antibody titer to the virus in the normal range) significantly reduced the amounts of virus shed from the noses and airways of RSV-infected owl monkeys.
Hyperimmune globulins, i.e., immune globulins having higher than normal titers of a particular antibody, are therapeutically useful in treating patients deficient or in need of that particular antibody. For example, tetanus hyperimmune globulin is useful in treating tetanus, and rabies hyperimmune globulin, rabies. It is well known that hyperimmune globulins can be produced from plasma or serum obtained from selected donors who have significantly higher titers for a specific antibody than is normally found in the average population. These donors have either been recently immunized with a particular vaccine (U.S. Pat. No. 4,174,388) or else they have recently recovered from an infection or disease [Stiehm, Pediatrics, Vol. 63, No. 1, 301-319 (1979)].
Accordingly, there is a need for an RSV immune globulin product having a higher than normal titer of antibody to RSV, especially one that may be administered intravenously.